feat: add package checksum tracking and re-extraction logic

cli/cmd/download_package.go

@@ -133,5 +133,13 @@ func (c *DownloadPackageCmd) DownloadBuild(p portal.Portal, build portal.Build,
 		return fmt.Errorf("failed to verify artifact: %w", err)
 	}
 
+	if download.Artifacts[0].Md5Sum != "" {
+		checksumFilename := fullFilename + ".md5"
+		err = c.FileWriter.WriteFile(checksumFilename, []byte(download.Artifacts[0].Md5Sum), 0644)
+		if err != nil {
+			log.Printf("Warning: failed to save checksum file: %v", err)
+		}
+	}
+
 	return nil
 }

cli/cmd/download_package_test.go

@@ -183,6 +183,32 @@ var _ = Describe("DownloadPackages", func() {
 			Expect(err).NotTo(HaveOccurred())
 		})
 
+		It("Saves MD5 checksum to sidecar file when available", func() {
+			md5Sum := "d41d8cd98f00b204e9800998ecf8427e"
+			buildWithMd5 := portal.Build{
+				Version: version,
+				Artifacts: []portal.Artifact{
+					{Filename: filename, Md5Sum: md5Sum},
+					{Filename: "otherFilename.tar.gz"},
+				},
+			}
+			expectedBuildToDownload := portal.Build{
+				Version: version,
+				Artifacts: []portal.Artifact{
+					{Filename: filename, Md5Sum: md5Sum},
+				},
+			}
+
+			fakeFile := os.NewFile(uintptr(0), filename)
+			mockFileWriter.EXPECT().OpenAppend(version+"-"+filename).Return(fakeFile, nil)
+			mockFileWriter.EXPECT().Open(version+"-"+filename).Return(fakeFile, nil)
+			mockFileWriter.EXPECT().WriteFile(version+"-"+filename+".md5", []byte(md5Sum), os.FileMode(0644)).Return(nil)
+			mockPortal.EXPECT().DownloadBuildArtifact(portal.CodesphereProduct, expectedBuildToDownload, mock.Anything, 0, false).Return(nil)
+			mockPortal.EXPECT().VerifyBuildArtifactDownload(mock.Anything, expectedBuildToDownload).Return(nil)
+			err := c.DownloadBuild(mockPortal, buildWithMd5, filename)
+			Expect(err).NotTo(HaveOccurred())
+		})
+
 		Context("Version contains a slash", func() {
 			BeforeEach(func() {
 				version = "other/version/v1.42.0"

internal/installer/package.go

@@ -17,6 +17,7 @@ import (
 
 const depsDir = "deps"
 const depsTar = "deps.tar.gz"
+const checksumMarkerFile = ".oms-package-checksum"
 
 type PackageManager interface {
 	FileIO() util.FileIO
@@ -73,8 +74,52 @@ func (p *Package) alreadyExtracted(dir string) (bool, error) {
 	return isDir, nil
 }
 
+func (p *Package) getPackageChecksum() string {
+	data, err := p.fileIO.ReadFile(p.Filename + ".md5")
+	if err != nil {
+		return ""
+	}
+	return strings.TrimSpace(string(data))
+}
+
+func (p *Package) getExtractedChecksum(workDir string) string {
+	data, err := p.fileIO.ReadFile(path.Join(workDir, checksumMarkerFile))
+	if err != nil {
+		return ""
+	}
+	return strings.TrimSpace(string(data))
+}
+
+func (p *Package) saveExtractedChecksum(workDir, checksum string) error {
+	if checksum == "" {
+		return nil
+	}
+	return p.fileIO.WriteFile(path.Join(workDir, checksumMarkerFile), []byte(checksum), 0644)
+}
+
+func (p *Package) packageChanged(workDir string) bool {
+	packageChecksum := p.getPackageChecksum()
+	if packageChecksum == "" {
+		return false
+	}
+
+	extractedChecksum := p.getExtractedChecksum(workDir)
+	if extractedChecksum == "" {
+		log.Println("No checksum marker found in extracted directory, will re-extract to ensure consistency.")
+		return true
+	}
+
+	if packageChecksum != extractedChecksum {
+		log.Printf("Package checksum changed (was: %s, now: %s), will re-extract.", extractedChecksum, packageChecksum)
+		return true
+	}
+
+	return false
+}
+
 // Extract extracts the package tar.gz file into its working directory.
 // If force is true, it will overwrite existing files.
+// If the package checksum has changed since last extraction, it will also re-extract.
 func (p *Package) Extract(force bool) error {
 	workDir := p.GetWorkDir()
 	err := os.MkdirAll(p.OmsWorkdir, 0755)
@@ -86,11 +131,19 @@ func (p *Package) Extract(force bool) error {
 	if err != nil {
 		return fmt.Errorf("failed to figure out if package %s is already extracted in %s: %w", p.Filename, workDir, err)
 	}
-	if alreadyExtracted && !force {
+
+	// Check if the package has changed since last extraction
+	needsReExtraction := p.packageChanged(workDir)
+
+	if alreadyExtracted && !force && !needsReExtraction {
 		log.Println("Skipping extraction, package already unpacked. Use force option to overwrite.")
 		return nil
 	}
 
+	if needsReExtraction && !force {
+		log.Println("Package has changed, re-extracting...")
+	}
+
 	err = util.ExtractTarGz(p.fileIO, p.Filename, workDir)
 	if err != nil {
 		return fmt.Errorf("failed to extract package %s to %s: %w", p.Filename, workDir, err)
@@ -105,6 +158,12 @@ func (p *Package) Extract(force bool) error {
 		}
 	}
 
+	packageChecksum := p.getPackageChecksum()
+	err = p.saveExtractedChecksum(workDir, packageChecksum)
+	if err != nil {
+		log.Printf("Warning: failed to save checksum marker: %v", err)
+	}
+
 	return nil
 }
 

internal/installer/package_test.go

@@ -153,6 +153,103 @@ var _ = Describe("Package", func() {
 					Expect(err.Error()).To(ContainSubstring("failed to ensure workdir exists"))
 				})
 			})
+
+			Context("when package checksum changes", func() {
+				var checksumFile string
+
+				BeforeEach(func() {
+					checksumFile = pkg.Filename + ".md5"
+					err := os.WriteFile(checksumFile, []byte("original-checksum-123"), 0644)
+					Expect(err).ToNot(HaveOccurred())
+
+					err = pkg.Extract(false)
+					Expect(err).ToNot(HaveOccurred())
+				})
+
+				It("re-extracts when checksum changes", func() {
+					workDir := pkg.GetWorkDir()
+					markerFile := filepath.Join(workDir, ".oms-package-checksum")
+					Expect(markerFile).To(BeAnExistingFile())
+					content, err := os.ReadFile(markerFile)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(string(content)).To(Equal("original-checksum-123"))
+
+					testFile := filepath.Join(workDir, "test-file.txt")
+					err = os.WriteFile(testFile, []byte("modified content"), 0644)
+					Expect(err).ToNot(HaveOccurred())
+
+					err = os.WriteFile(checksumFile, []byte("new-checksum-456"), 0644)
+					Expect(err).ToNot(HaveOccurred())
+
+					err = pkg.Extract(false)
+					Expect(err).ToNot(HaveOccurred())
+
+					actualContent, err := os.ReadFile(testFile)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(string(actualContent)).To(Equal("test content"))
+
+					content, err = os.ReadFile(markerFile)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(string(content)).To(Equal("new-checksum-456"))
+				})
+
+				It("skips extraction when checksum is the same", func() {
+					workDir := pkg.GetWorkDir()
+					markerFile := filepath.Join(workDir, ".oms-package-checksum")
+					Expect(markerFile).To(BeAnExistingFile())
+
+					testFile := filepath.Join(workDir, "test-file.txt")
+					err := os.WriteFile(testFile, []byte("modified content"), 0644)
+					Expect(err).ToNot(HaveOccurred())
+
+					err = pkg.Extract(false)
+					Expect(err).ToNot(HaveOccurred())
+
+					actualContent, err := os.ReadFile(testFile)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(string(actualContent)).To(Equal("modified content"))
+				})
+
+				It("re-extracts when marker file is missing", func() {
+					workDir := pkg.GetWorkDir()
+					markerFile := filepath.Join(workDir, ".oms-package-checksum")
+
+					err := os.Remove(markerFile)
+					Expect(err).ToNot(HaveOccurred())
+
+					testFile := filepath.Join(workDir, "test-file.txt")
+					err = os.WriteFile(testFile, []byte("modified content"), 0644)
+					Expect(err).ToNot(HaveOccurred())
+
+					err = pkg.Extract(false)
+					Expect(err).ToNot(HaveOccurred())
+
+					actualContent, err := os.ReadFile(testFile)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(string(actualContent)).To(Equal("test content"))
+				})
+			})
+
+			Context("when no checksum sidecar file exists", func() {
+				BeforeEach(func() {
+					err := pkg.Extract(false)
+					Expect(err).ToNot(HaveOccurred())
+				})
+
+				It("skips extraction without checksum (backward compatibility)", func() {
+					workDir := pkg.GetWorkDir()
+					testFile := filepath.Join(workDir, "test-file.txt")
+					err := os.WriteFile(testFile, []byte("modified content"), 0644)
+					Expect(err).ToNot(HaveOccurred())
+
+					err = pkg.Extract(false)
+					Expect(err).ToNot(HaveOccurred())
+
+					actualContent, err := os.ReadFile(testFile)
+					Expect(err).ToNot(HaveOccurred())
+					Expect(string(actualContent)).To(Equal("modified content"))
+				})
+			})
 		})
 	})